Gyroscopic pilot for aeroplanes



May 6, 1930. 1 B. sPERRY 1,757,096

Y GYROSCOPIC P`ILO'I*` FOR AEROPLANES vOriginal Filed Aug. 1, v1916 2 Sheets-Sheet Z INVENTOR LnwRE/vc: B. .SPERRM I TTOR/VE Patented May 1930l I l UNITED fsrA'ras PATENT," olf-FICE LAWRENCE B. SPEBRY, 0F BROOKLYN,` NEW YORK, ASSIGNOR, BY MESH-E ASSIGN- IENTS, TO SPEBBY-GYROSCOPE COMPANY, INC., OF BROOKLYN, NEW'` YORK, A. COIB-l POBATION OF NEW YORK GYROSCOPIC PILOT FOR .AEMPLANES Application mea August 1, 1916, sex-iai This invention relates steering devices time enable vit to be brought under theinstant control of the aviator. l A further object of the invention is'to provide means whereby anaircraft may be iown upon a predetermined courjseandv also with 4extremely accurate azimuth indicator such asl means whereby the said course may be vchanged atwill.

The principal elements f my device comprise a `small gyro'scope of simple design, adapted to maintain a constant position in azimuth for a fairly long period of time, and

` a servo-motor controlled from saidl gyroscope and connected with thehrudder. In navigating aircraft it is not necessary to. provide an the'Sperry gyroscopic compass, as the shifting currents of air will carryy the aviator off his course sooner or later, even if the aeroplane is under the control of themost'precise gyroscopic compass. I therefore propose to make use of a comparatively small compass, *which will maintain its position in azimuth with a'A fair degree of accuracy, and to makeA4 partly in section, of a gyroscopic unit, de-

signed according to my invention for use in steering an aeroplane or other dlrigible ves' sel.

l Figg is a front elevation of the same, a few" parts being in section. A y Figures 3 and 4 are a plan and side view respectivelyof :a spring washer used in the 1 gyroscope.

\ Fig. 5 is a detail,fand Fig. 6 a front elevation of a device. which I lterm a centralizing ,'member.

1ro. 112,505. Renewed January 2,1930.

Fig. is a longitudinal section of the stolef,

noid vadapted to control said centralizillg'-A member.

Fig 8 is a diagrammatic view and diagram illustrating the application of my? invention to an aeroplane.

Takmg up first my preferred form of gyrowhlchf is mounted av vertical bracket 2. With- J 1n vertical bearings 3 and 4 in the ring and base respectlvely is rotatably mounted a ver-' tical or gimbal ring 5, within which the rotor bearing casing or-gimbal `6 is pivotally su'pported on horizontal pivots 7 and '8. All of thepivots mentioned are equipped withl antifriction-bearings 9, andeach set is provided with a special take-up device adapted to compensate for wear in the ball bearings and to thereby. prevent any end-wise play in thepivots. 'This device may comprise a set screw 10 or other adjustable device adapted to clamp and the end of the pivot. 1 2 on the ring or casing. The other end ofthe bearing is also supported on a ball 11. An index 120 may v beattached to ring1 ing cha s in the eading'of the aircraft by oopxratmghwith a suitable scale 121 on ase- the casing 6 and is-preferably constructed as an, integral part of a polyphase induction motor. The stator of said motor is Vplaced -upon a fixed shaft 13 supported withinv the casing, and upon said stator are placed all of the polyphase windings. The rotor may be of standard squirrel cage construction as fary as electrical features are concerned. Mechanically it is made, however,`in the form of a heavy ily-wheel 14 journalled upon said,

shaft 13 on anti-friction bearings 15. awill The gyroscopeproperis mounted within scopic unitz-l denotes a suitable base on upon a ball 11 situated between'said screw' 5, if desired forindicatA I be seen in 4this construction that the rotorv completely encloses the statorand thus gives a maximum moment of inertia to the rotating parts. The wires 16 are brought into the stator through one end of shaft 13, which is of the shaft or stator a small washer-'22 which is split and sprung apart somewhat as indicated in Fig. 4, so that the resilience of the washer will take u any end pla that may exist, or that ma be caused by t e wearing down of the ball earings. ,l

An adjustable Weight 17 is shown threaded upon a shaft 18 secured to the'ring 5 for the purpose of adjusting the balance of the gyroscope about the vertical axis. The bal-- ance about the horizontal pivots 7 land 8 is adjusted by means of'a threaded weight 19 mounted upon shaft 13 oi' an extension thereof. Weight 19 may also be used to adjust the balance of the gyroscope for diferent latitudesin order to cause precession of the gyroscope at the required rate to keep up with the earth. A ring 20 provided with a series of holes 21 may also .he lused for adjusting the balance by placing small weights inthe va# rious holes. i, These refinements are very essential tothe proper operation of the gyroscope, it being important that the gyroscope be balanced about each of its three axes.: The

aeroplane isv controlled from a gyroscope in" directly by means of electric contacts which operate a servo-motor connected to the rudder. The contacts are shown. as consisting of a pair of4 conducting segments 23 and 24' of the pinions 102 is shown as mounted on the same shaft 104 as a fan or 105,'which is driven by the air currents caused by the {iightof the aeroplane. The Windings27 and 28 are adapted to force the adjacent gear into contact with a clutch disc 106 secured to shaft 129, s'o that it may,be driven in either direction. Follow up wires 33 from drum 34 are wrapped upon a drum 108 driven from shaft 129 through suitable gearing, 109, while the rudder wires 31 and 32 engage a similar drum 110.

The servo-motor is notonly connected to the rudder 30 by meansof wires 31 and 32, but is also connected with the gyroscopic unit so that a' follow-upv connection is provided betweenz the two. The principal object of the follow-up connection is toreduce or prevent hunting of the aeroplane, in azimuth, about ,J n o its predetermined course. This connection may consist of a wire 33 extending Lfrom the servo-motor around a drum 34 mounted adjacent' to the gyroscope.. Secured to said drum 1s one emember 35 of an electro-magnetic clutch, the other member 36 of which is noi-- mally held disengaged therefrom by spring 37 but is 'clutched thereto on excitation of v,The said segment carrying trolley 26 by means of a link 41 -so or brush 26 bears upon' insignes winding 38,. Member 36 is provided witha pinion 39 meshing with a vgearsegment 40. 1s connected to the block 42 that when the clutch is enga ed a follow-up motion will be imparted to t trolley from the servo-motor or other part of the steering apparatus. 1 v y The trolley block 42v isjmounted upon an arm 44 pivotally supported on a boss 43 extending from base 1. Also mounted 0n or near said base are a pair of spaced leaf sprin s 46 which engagey over anjupwardly exten ing .pin 4.7 on said basel and downwardly extendingpin'48 on the arm 44. The

pins are solocated that the trolley is normal- 1y positioned between the two contact strips 23, 24. It will be seen that as .lon as the clutch is engaged the trolley 26 Wil follow the movements of the servo-motor,-but as soon as it is disengaged the trolley Willbe returned to its centralized position with respect l.to said reversing contacts by springs 46.

On the-opposite side of the gyroscope from the drum is shown a special device which I employ to bring the gyroscope quickly back to a ,predetermined relation ,or centralized position with respect to the aeroplane at the will of the aviator. This dev-icei consists of tapering orv conical shaped member 50 adaptedl to be moved toward the gyroscope and to engage a stem 51 extending from the .casing or inner gimbal 6 of the gyroscope.

Member 50 is preferably provided withA inwardly extending radial blades` or .ins 52 which perform the Vimportant function of stopping the precessional movements of the gyroscope. Without some such means any attempt to move the 'gyroscope directly to a new position would onlyx result in precession of the gyroscope at right angles to the application of the force, but by applying a force a in therequired directionand at the saine time stopping the precession, the gyroscope may vbe brought quickly to any desired position;

Member 50 is controlled by means of a solenoid 53, the said member being secured to an extension 54 of the core 55 of the solenoid. A spring 56 is provided to hold the member 50 normally in the engaged position. On excitation of thesolenoid, member 50 is quickly withdrawn out of the path of the stem 5 1. I

prefer to provide means for reducing the cur' rent flowing vthrpugh the solenoid after the core has been drawn iully within it, since a greater current is required to bring the core to this positionV than to hold it there. For

this purpose we have provided a switch 57,

which is opened when the core is in the' innermost position as shown in Fig. 7. This switch is connected so as to cutout or short circuit aresistance 58, which is otherwise Vconnected with the winding 60 of the solenoid (see Fig. 8)

The means directly controlled by thev aviator for actually controlling 'the rudder ist represented in F-ig. 8 at 61. As far as this invention is concerned, said means may comprise any suitable form 'of handle, foot pedal, or other controlling means, but which has incorporated therein a novel form of. switch. The controlling means is shown as a foot pedal made in two parts, 62 and 63, hinged together at 611.'- One half of a twd part contact button 65 is placed upon eachl lever so that when the levers are rotated in opposite directions a slight distance from `the position shown in figure. 8 the` circuit will be opened. A strong-compression spring 66 is provided to hold the contacts normally closed.v It will be seen however, that as soon as thej aviator pushes upon either or both levers te ,.rotate tthe rudder, the compression 'spring'will yield andthe button open. This will not, however interfere with the steering o f the craft asthere is always suiicient give to the wires 67 and 68 extending from the pedal to the rudder to allow for this slight `lost motion.

- Button 65 is in circuit not only with magnetic clutch winding 38, but also withn the servo-motor andthe solenoid 60, so that the,v effect of opening the-button will be: c 1st, to sever tli'e follow-up connection between the servo-motor'andthe gyroscope. 2nd, to, cut out the servo-motor and renf der it inoperative.` .d 3rd,'to automatically centralize the gyro- I find in practice, however, that it is not necessary to disconnect the follow-up connections between the servo-motor Vand the gyroscope so thatclutch 38 andassociated parts maybe omitted if desired.

By a further movement of the foot" pedals the aviator can then shift the 'rudder 30 direetly to a new'position. .Upon release of will again be energized, the following-up i connection completed,'andtl1e gyroscope re' leased, s othat the automatic pilot will take up the steering of the aircraft where the aviator left itand maintain it on its course 'until' the aviator again desires to change the i course -or to correct for side drift. V Another systemfor correcting for `side drift-Which may be effectively employed is to couple the gyroscopic unit or some partv connected therewith. to adrift indicator such as disclosed in 'my Vcopendingl application-', Steering device for aircraft, filed March 24th,

i 1915, now matured into Patent No. 1,390,653, dated September 13, 1921,. For this purpose the'entire gyro-unit may be pivotally mounted 6.0 on a'base 100 so that it may be readily rotated from a sighting device 1015 by means 'of wires 102 or the like. As shown in Fig. 2, Wires 102' are Wound about base 1 to turn th'e latter, f on base 100. The turning of base 1, ofcourse,

f5 shifts brush or trolley 2 6, while contacts 23 the rudder in-this`position the servo-motor' 'f and 24 are maintained relatively stationary by contacts 23, 24 and to brush26, the wires 102 i are shown as connected-to the contacts in Fig. 8. The 'sighting device consists in a small telescope, 103 rotatably mounted about a vertical axis in a bracket104; The telescope is provided with a line or cross hairs 105 adapted to be lturned in the direction of the true line of flight, as observed bythe direction ofthe streamlines' seen through the telescope. The telescope is connected to a compass 106 so-that when it is turned, the lubbers line 107 of the compass will be correspondingly shiftedl to a position 107 say. Without .a

'connection such as wires 102', the-observer would then move the pedals 61, 62 so as to turn the machineh back through anangle approximately equal to the angle thrcugh .which'line 107 has been moved. fires 102 are so connected, however, that the gyroQunit,

is turned'backw'ardly 4 through the angle, so

` that, as the telescope is being turned the unit is turned in the opposite direction and the rudder 30 'turned by means of the 'servo-motor through the correct angle to bring the lmachine to the correct course. l l

It vshouldalso be observed when the'base 1 is rotated by wires 102 by. the observer thrdugh his rotation of the sighting dev-ice that the reading of pointer .120 on `its'scale 121 is changed, since the latter is mounted on base-1 and the former is held stationary by the gyro'scope. When the gyroscope of my invention .is being used as a Hight indicator,v

the observer ati the sighting device may readily sh ow the pilot atthegyroscope when to make-the desired change of course. The pilot thereupon brings the aeroplane around until the pointer again reads at the proper; reading on the scale. 'If no pilot is used, this unction 'is accomplished ,1 automatically asdescribed.'

In accordance with-the provisions of th'e patent statutes,..-'I haveherein described the principle of operation of my. invention,

together with the apparatus, which'I no'w consider to represent the best 'embodiment thereof, but I desire-to have it understood paratus shown is only illustrative and that. t e inventioncanbe carried out by other' means.' Also, whileit is 'designed to use the various features and elements in the combination *and relations desk'xribecl, some of these maybe 'altered and'others .omitted withoutix-terfering'with the 'more general results outlined to such use. l

Having described my i claim and desir 1. In an automatic'pilot foraircraft, the combination with the vertical rubber, of a gyroscope .for normally controlling the saine to and, the invention extendsA i 5 rudder and altered, and means means for severing scope the other 'lcontrolled from said gyroscope, and means brought into action Yby movement of said first named means for centralizing said gyroscope.

3. In an automatic steering device for the comblnation with a vertical means for controlling the/same -at will, of a gyroscope, a'servo-motor, connections-between the servo motor, rudder and gyrosco e and means responsive to movement o said first namedmeans for severing the connections between-said servo-motor and the gyroscope, whereby the course may be for restoring said connecto maintain the aeroplanes,

tions after said movement new course. i

4. In an automatic pilot for aircraft,in combination with a rudder a gyroscope',

servb-motor, connections between the servomotor, rudder and gyroscope including a primary connection and a followup connection between said gyroscope and said motor, and means for changing the course' of the aircraft comprising means for turning the rudder and means for severing said connections between the servo-motor and the gyroscope while the rudder is being turned.

5. In an automatic pilotA for aeroplanes, A

combination with a vertical rudder,

the combination with a rudder and a manual control device therefor, of a gyroscope, a servo-motor, connections between the servomot-or, rudder and gyroscope and means responsive to'movement of said manual device for severing the connections betweenv said servo-motor and the gyroscope, and for cen- -tralizing said gyroscope.

'Y 6. In an automatic pilot for aeroplanes, the combination with a rudder and a means for actuating the same at will, of a gyroscope, a servo-motor, connections betweenthe servomotor, rudder and gyroscope and Imeans responsive to movement of said first named the connections between said servo-motor and the gyroscope, for centralizing said gyroscope and for rendering said motor inoperative.

7. In gyroscopic apparatus for dirigible craft, the combination with a gyroscope having a plurality of degrees of freedom, of means for centralizing said gyroscope comprising a projecting member and`a hollowtapering member for engaging the same, one of said members being mounted on the gyroon a fixed part, means for imparting relative movement to said members and mea-nscontrolled by the relative position of said-craft and gyroseopkel for governing the course of thecraft..

8. In gyroscopic apparatus for 'dirigible aircraft, the combination with a gyroscope having a plurality of. degreesf freedom, of means for centralizing said gyroscope coinprising aV projecting member and a hollow tapering member for engaging the same, having inwardly projecting ribs', one of said members being mounted on the gyroscope the l l ber, said contacts comprising a contact segment and a co-operating brush, a clutch member adapted to engage and disengage said member, means for oscillating said clutch member, and resilient means for bringing the said contactsI to their neutral position when said clutch is released.

10. In an automatic pilot for aeroplanes, the combination with a vertical rudder and control device therefor, operable at will, of a. yroscope, a-servo-motor, means including a ollow-up connection'co'nnecting said servomotor, rudder and gyroscope and means responsive toA movement of said device for breaking said follow-up connection.

11. In a steering device for aeroplanesche o a servo-motor for controlling the same, a gyroscope, means for supporting the same for turning about a vertical axis and for oscillation abou a horizontal axis, means'operable by relative turning ofthe gyroscope and areoi for breaking said connection, and means forv changing the relation between said rudder and said second mentioned means while said connectionis broken.

12. In a steering device for aeroplanes the combination with a vertical rudder, of a servo-motor for controlling the same, a gyro'- scope, means for supporting the same` for turning about-a vertical axis,emeans operable by relative turning of the aeroplane and gyroscope about said axis for controlling said motor, a drift indicator, and means connecting said indicator and said other means for shifting the efective relation of said means, whereby the aeroplane is automatically brought on a true course.

13. In asteering device foraeroplanes the combination with a vertic l servo-motor for controlling t e same, a gyroscope, means for supporting vthe same for rudder, of a.

F.imsaoea turning about a vertical axis, meansoperable by.relative turning of the aeroplane and gyroscope about said axis for controlling said motor, a drift indicator, and means connecting said indicator and said gyroscope, whereby the effective relation of said other means is shifted and the aeroplane turned to correct for side drift.

14. In an automatic steering device for aircraft, the combination with 'a rudder and a servo-motor for controlling the same, of an azimuth indicator, means brought into action b relative turning'of the aeroplane and indlcator for actuating the servomotor,a drift indicator, and means connecting said indicators whereby the said first means are shifted to change their effective relation.

15. In a steering device for aeroplanes the combination with a vertical rudder, of a 2o servo-motor for controlling the same, a gyro-A scope, means", for supporting the same for turning about a vertical axis, means operable by relative turning of the aeroplane and gyroscope about said axis for controlling said motor, a drift indicator, a compass connected therewith so as to have its readings affected thereby, and means connecting said indicator, andsald other means for shifting the effective @relation of said means, whereby the aeroplane 23 is automatically broughton a true course. l

16. The combination with an aeroplane, of a steering rudder therefor, a gyroscope, a

servo-motor connected to said rudder, means` the aircraft. i

18. In an automatic pilot for aircraft, the combination with the vertical rudder, of a gyroscope for normally controllin the same to maintain the craft-on a pre etermined course, means for altering the course of the craft', including means for temporarily rendering the gyroscope control ineffective and centralizing said *gyroscope, and, means for turning the rudder to bring the craft to a new'cours'e.

19. dirigi le craft in combination, a gyro rotor, a Arotor bearing casing therefor, a qing .rotatable about'an axis, said ring supporting said casing for turning about a second axis, and means for centralizing the gyro casing about both axes comprising a member adapted to engage said casing and cause rotation i 55 `thereof toward the central position aboutV one for automatically changing the heading-of an automatic steering device for l axis while preventing movement away from the central position about the other axis and means controlled by the relative position of" said gyroscope'and craft to govern -the course thereof. Y

20. In an automatic pilot for aeroplanes, the combination with a rudder and a control devicetherefor of a' gyroscope, 'a servomotor connected with said rudder, means .operable by relative vturning of the gyroscope and aeroplane for controlling said motor, a follow-up connection from said rudder. to said means, and means responsive to movement of said control device for severing said followup connection and rendering said servo-motor inoperative.

21. In an automatic pilot rfor aeroplanes, the combination with a rudder and a` control device therefor, of a gyroscope, a servo-motor connected with saidv rudder, means comprising a -control member connected to said gyroscope andan independently mounted cooperating control member for governing said servo-motor from said gyroscope, and means brought into action by movement of said device for rendering said 'servo-motor inoperative and for moving the second mentioned control member into a definite position with respect to the other control member.

22. In a' steering device foraerplanes, the combination with a vertical r.udder,of a servo# motor foi` controlling the same, a gyroscope, fmeans, for supporting the same for turning about a vertical axis and for-oscillation about a horizontal axis, means operable by relative turning of the gyroscope and aeroplane' about a `vertical axis for controlling said motor,

means for shifting the relation-betweenlthe loo gyroscope. and rudder, for changing 'the course of the aeroplane, and a follow-up connection from the rudderto the second mentioned means.

23. yIn an automatic pilot for aircraft, the combination with the vertical rudder, of a gyroscope for normally controlling the same,

los

Vto maintain the craft on a predetermined course, control members mounted respectively on the gyroscope and aircraft, a servo-motor controlled therefrom and connected tothe rudder, and means for altering the course ofthe craft including means for vturning the rudder to bring thecraft to a new course,

means for throwing out of action the gyro control, and means for centralizing the control members while the gyro control is out of action.

combination with a vertical rudder, of a servo-motor for controlling the same, a gyro-- v scope, means for supporting the same for .turning abouta vertical axis and for oscilla-- '24. In a steering device for aeroplanes, the

rudder to the second mentioned and means mcludin a centralizing device for the Y gyroscopefor c anging the course steered by tie gyroscope during the iight of the aero- .p ane.

25. The combination with a pe 1ncluding a'gimbal rin provided with an axial projection, of a mem er arranged to reciprocate in a predetermined path coincident with a line extending )through the center of'said gimbal ring for resetting said gyroscope into a predetermined positlon.

26. The combination witha gyra-scope hav'- ing a gimbal ring provided with an extension', of amember having diverging walls movable into and out of-engagement wlth saidextcnsion through a predetermined path for 'controlling the operation of said gyroscope,

and `a power system arranged to move said member into and out of engagement with said gyroscope.

27. In oscopic apparatus for use in navigatin y aircraft, the combination with a ground o serving sight, means for turning erated from said rst named means for l the same :a gyroscope, an indicating means connected to said oscope, and means o tering said indicating means when it is desired to change the course.

In testimony whereof I have aixed my slgnaturel Y LAWRENCE B. SPEBRY. Y 

